Also, with Ford, they didn't set out to kill him. Ford died because he tripped and fell.

I'm just saying that if Nick is the killer, they need more than drug dependency to be the reason for his crime. Like self-defense or in defense of another or accidental.

Yea but I don't think Nick set out to kill Trent either. It was Melanie who brought the knife to the murder scene so unless he brought something else but decided to use a weapon of convenience, I think this will be an accidental death.

Of course, the doesn't excuse his behavior of trying to gaslight Melanie which I still feel is totally OOC for him.